Here's the Parts List and Cost Breakdown...
The Best thing you can do is troll craigslist and ebay for cheap paintball tanks... Might as well get the 20 oz tanks don't see any reason to go small. False economy... I got a 20oz tank and a On Off Valve off of craigslist for 20 bucks... MAKE SURE THE HYDROTEST DATE IS GOOD! You don't want to go through the hassel of hydrotesting a tank extra $$$...Also ebay and craiglist is the best way to get the tanks, on off vavle, and the regulator...Also get two tanks...If you can. So you always have a full one ready to go. If that is out of your price range well then just get one...
1. Teflon Tape - Home Depo
2. Coupling - Home Depo
3. Washers - Home Depo
4. Paintball Tank 20oz - Craigslist / Ebay
5. Paintball On Off Vavle - Ebay
6. Co2 Line - Ebay / LFS
7. Co2 Glass Diffuser - Ebay
8. Co2 Check Valve - Ebay
9. Co2 Regulator - Ebay
10. Co2 Drop Checker - Ebay
11. Co2 Needle Valve / 2 Way Splitter ( Optional ) - Ebay
Cost List With Tax and Shipping Included
Teflon Tape and Coupling $3.56
Paintball Tank w On Off Valve $20
Second Paintball Tank $20
Second On Off Valve $15.42
Galss Diffuser x 2 $6.99
Co2 Tubing $4.99
Co2 Check Valve $5.00
Co2 Drop checker $ 8.50
Co2 Needle Valve / 2 Way Splitter ( Optional ) $15.65
Total Cost $124.47
That's from Scratch and going with an extra tank and on off valve.
Cheapest Price Possible One tank, No check valve useing a diffuser you allready have and other things on hand etc...
Total $47 give or take a few
So here comes the sweet graffics and explanation part.....
Regulator from Ebay just search for co2 regulator and they come up...
Here's a picture of the regulator with the gague that I'm pretty sure would work cost about $10 more than the cheap-o one I got.
The Coupling I used...$ 2.49 plus tax @ home depo
Here's a Link To a Pro one that cost $15 plus shipping...
The washer Used to make an airtight seal between the tank and the coupling. Not sure how long it will last as the co2 will probably eat away at it but they are cheap and you get two and only need one...
The On Off Valve For the Paintball Tank. You need this because the normal valve that comes with the Paintball tank is a pin valve and the regulator / coupling won't push the pin down to let the gas out. This Lets you turn the gas on and off with ease as well. If you get the $15 dollar pro coupling it'll work without the need for the on / off valve.
I'm going to get the optional Co2 Needle Valve / 2 Way Splitter as i like having two glass diffusers in my tank as the flow rate is really high and it ensures a good spread of the co2 throughout the tank... With the splitter you could run the co2 to two tanks!
The Glass Diffuser to diffuse the co2 into the tank... you could also use a co2 reactor or anything of your choice to get the co2 into the water...
A check valve is important! But.... I'm not running one. It stops water from crawling up the co2 line and entering the co2 tank. It's a one way flow valve here's a picture of one for love...
Co2 line is resistant to co2 as some line will be eaten away by it and others will let the co2 leak out...
Drop Checker lets you measure the amount of co2 in the water. At it's best it is 30 to 60 minutes behind. So after your tank hits the right co2 lvl 30 to 60 minutes later the color will change to green.... There are other good write ups out there about drop checkers I'm not going to explain it all here... Here's a photo of one for good measure though
Here's what my system looks like all put togeather. If you go my cheap route You'll have to test things to make sure it isn't leaking and also there is the possibility of when the tank gets low all the co2 turning to gas and flooding the tank...( not sure if that is going to happen ) the optional needle valve might help with that not sure.... Put Teflon tape on the treads on the tank and on the coupling to help prevent any co2 leaks...
Any question please just PM me!